Two-cycle gas-engine.



G. P. JENKINS. TWO-CYCLE GAS ENGINE. APPLICATION FILED 1107.18, 1910.

Patented July 4, 1911.

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IVITNESSES- I LVVEN T 01?. g

C. P. JENKINS. TWO-CYCLE GAS ENGINE. APPLICATION FILED NOV. 18, 1910Patented July 4, 1911.

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7 ////////////6V/ 5 /////////g w -1 III WITNESSES:

CHARLES FRANCIS JENKINS, OF WASHINGTON, DISTRICT OF COLUMBIA.

TWO-CYCLE GAS ENGINE.

pecsflcation of Letters Patent.

Patented July 4:, 1911.

Application filed November 18, 1910. Serial No. 593,028.

I To all whom it may concern:

Be it known that I, CHARLES FRANCIS JENKINS, citizen of the UnitedStates, residing at Washington, District of. Columbia, have inventedcertain new and useful Improvements in Two-Cycle'Gas-Engines, of

. which thefollowing is a specification.

This invention relates to that class of gas engines known as two-cycleengines.

It has for its object an engine which can be throttled down until itturns over slowly and explodes evenly under light loadiand when runningidle. This is accomplished by placing the sparkingdevice at the pointwhere the gas enters the combustion space-.

The two-cycle motor is notoriously waste,-

ful of gasolene in automobile use' on the comparisons of the two-cyclewith four-cycle average road surface. This comes about not because themotor 1s not as efficient at hard work as. the four-cycle motor, butprincipally because, unless the motor is working atnear its maximumcapacity, there is too large a proportion of the carhureted charge mixedwith the burned gas of the previous explosion. Fully nine-tenths of allautomobile work is done at a rate much below fifty per cent. of themaximum power of the motor, that is, the motor is working underthrottled charge the greater portion of the time. This means that muchof the good gas is so mixed with the bad gas at the point of highestcompression that considerable of the gasolene vapor is never burned atall. Beside the waste of gasolene, it is noticeable in the bad-smellingexhaust. In many motors under like conditions this loss has been foundto average about ten to twenty in favor of the four-cycle, that is, thefour cycle motor will work a given weight of car twenty miles per gallonof gasolene, while the two-cycle motor under the same conditions willonly make ten miles to the gallon. This is accounted for in severalminor ways, but the principal advantage the four-cycle motor has overthe two-cycle is in the fact that the spark-plug is located at the gasinlet and in such manner that it fires small charges as efficiently aslarge charges, or practically so. This is not true in the usualconstruction of the two-cycle motor for the reason that the spark plugis located at a point the farthest removed from the gas inlet. If,however, the spark plug could be as advantageously located in atwo-cycl'e best practice in four-cycle motors there should be acorresponding efiiciency. This efficiency would come about also becausethe spark could be advanced to its most. advantageous position while thecharge could be reduced to the least possible amount necessary to keepthe motor turning. Obviously less heat would be wasted in the coolingjacket especially when running idle. No two-cycle engine, as at presentconstructed, will run idle without missing, while the four-cycle motorhas been so developed and perfected that it not only runs idle withoutmissing, but so slowly and quietly as to be motor, as in theconstruction shown by the practically noiseless. The trouble is that thesmall charges in the two-cycle engine will not fire becausethey are somixed with the bad gas of the previous explosion. Necessarily the chargemust be increased until there is a preponderance of good gas and thespeed of the carcontrolled to such an extent as is possible by retardingthe spark. As is well known to gasolene motor engineers, economy andefficiency is obtained by an advanced spark and a throttled charge. Thishas, to the present time, 'in two-cycle motors, been an impossibility,principally because as stated above the spark plug is placed at the mostremote position, insteadof being placed so that it sparks in a charge ofgood gas no matter how small the charge. If the firing begins in goodgas then practically all the gas is converted into power, while, if thespark occurs in a poor mixture, the mixture is fired with di'fiicultyand often not at all until enriched by the second charge. The result iserratic running and uneven firing, that is, running light the motorstutters.

The present construction incorporates the desirable features of a fourcycle motor, that is, economy of gas with silent running and evenexplosions while running idle or at light work, while at the same timeretaining all the features of simplicity of construction, easy cooling,etc, of the ordinary two-cycle 'motor. Heretofore when this desirableend was sought to be accomplished, baiiie-plates, pockets, or otherconfining and irregular shapes were employed on the top of the pis ton(usually), and these, getting red hotby the enveloping flame of theexplosion, ignited the gas as it entered, and before the spark plug gota chance to fire the charge,

stroke; Fig. 2 .is "a similar sectional view the piston is down, putsthe crank-case in ment of the invention the spark 'the piston; 7"thewateracket spaces; 8 a

- vice for firing 8, as explained. in Patent No.972,379, is to preventback-firing. And this device, whether multi-tubular or gauze, is usuallytermed a screen, and in the claims this is what is meant.

. What I claim is 1. In a gasengine, reciprocating therein, 2. locatedoutside of the the water-jacket space upper end of the communicationcylinder,

thus creating back-pressure, loss of power, an excessively hot engine,etc., defeating the very end sought.

In the construction shown in the present plug is placed at the point ofingress of the gas, and in a con-- fined passage, and overheatingprevented by having this narrow passage water-jacketed.

In the drawings, Figure l is a sectional view of an engine cylinderconstructed in accordance with this invention, and having a pistontherein at the top of the piston a cylinder, a piston longitudinal passae cylinder but within of said cylinder, the passage being in open withthe upper end of said :with the piston at the bottom of its stroke;opened and closed by the reciprocation of Fig. 3 is a; verticalsectional view of the pisthe piston, and a spark-plug located at theton; and Fig. 4 a cross section view of the lower or ingress end of theassagepiston, on line w-y. 2. In a gas engine, a cyhnder, a iston In allthe figures like symbols refer to like parts, in which 1 is a cylinderof the. engine; 2 a piston therein; 3a connecting rod; i an exhaust.

port; '5 a combustion passage in communication with the combustion space6 above reciprocating therein, a longitudina passage located outside ofthe cylinder but within the water-jacket space of said cylinder, theupper in open communication with the upper en of saidcylinder, the lowerend adapted to be opened and closed by thereciprocation of the piston, aspark-plug located at the lower or ingress end of the passage, saidpiston having a plurality of rings so located .thereon as to lie on eachside of the ingress end of the passage when the piston is at the upperend of its stroke.

' In a gas engine, a cylinder, a piston Qreciprocating therein, alongitudinal passage located outside of the cylinder but within thewater-jacket space of said cylinder, the upper end of the passage beingin open communication with the'upper end of said cylinder, the lower endadapted to be ;opened and closed'by the reciprocation of the piston,said piston having a plurality tubular passage in the piston which, whencommunication with the combustion passage; 9 a spark-plug, or othersuitable dethe charge; and 10 piston rings of which nine are shown.

The operation of the engine, obvious to those skilled in the art, is asfollows: Carbureted gas is drawn into the crank-case from the carburetor(not shown) in the usual manner, 6. e., by the upward movepiston; and byits downward movement is 'forced through the tubular passage 8 into thecombustion passage 5, driving ahead of it the bad gas remaining afterthe revious xplosio -;If the throtof rings thereon so located as to lieon each tle is wid e. open the combustion space 6 Slde 0f theingress'end of the passage when above the piston will be completelyfilled, the piston is at the upper end of its stroke. and on theignition of the charge the maxi- In g S engine, a cylinder, a piston mumpressure will be exerted on the piston. r lpr catlng therein, alongitudinal pas- If, however, the throttleis but slightly open g edutside of the cylinder but .the' combustion passage only may be fill dwithin the water-jacket space of said cylinand none overflow into thecombustion cler, theupper end of the passage being in space above thepiston. This small charge open communication With'the upper end of willbe just as efiicient in proportion to its said cylinder, the lower endadapted to be volume as was the larger charge for it was opened n Closedby e r ciproc tion of compressed to practically the same extent the pin. a Piston ha ing a Screened and none was mixed with the bad gas of thebypass therein communicating with the previous explosion. It will,therefore, be a p g Wh n th pi t n is at the lower obvious that thespark-plug is always swept 6nd ts S roke.

by the fresh charge, be it large or small, and In t im ny r of I havea-fiiXed my the ignition hwill Ibo just as t i i one signature inpresence of two witnesses.

case as in t e ot er, althou h the 'char e and consequent impulse may beonly ju t CHARLES FRANCIS JENKINS ,sufiicient to keep the engine turningover, Witnesses:

and without missing a single explosion. G. Love,

he purpose of, the multi-tubular passage JAMES L. CRAWFORD.

a Copies of this patent'moy be obtained for five cents each, byWashington, 110.

end of the passage being the lower end adapted to be

